Meter seal and stop mechanism



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Filod Jun. 21, 1944 H IGH PRESSURE CHAMBER METERING ELEMENT ngwd Tonner T MVM 0 ww 1 f Patented Mar. 11, 1947 este METER SEAL AND STP MECSM Francis W. Guibert, Beverly Hills, and Frederic B. Fuller, Whittier, Calif.; said Fuller assigner to said Guibert Application June 21, 1944, serial-No. 541,354

(c1. 1oz-116.5)

' 5 Claims. 1

This invention relates to a sealed transmission, preventing escape of fluid under pressure from a closed container, While permitting mechanical transmission of motion through the seal.

One application of such a seal is found in iluid metering devices in which the metering element is placed in the path of flow of the fluid, motion of the element being transmitted to a register, or indicator, external of the metering element.

High pressure liquids or fluids requiring such metering are, for example, butane and propane, which are capable of forming a highly explosive mixture with air in the event such gases escape through the seal. When it is' considered that pressures as high as 300 pounds per square inch are used in containers for such uids, it becomes apparent that a thoroughly reliable sealing means must be provided which will be capable oi withstanding wear for extended periods.

Ordinary packing glands have been proposed for such service, but wear unduly and are, therefore. impractical; and leaks are apt to develop that becomes progressively worse and, ultimately, an intolerable rate of escape of the fluid is encountered.

It is one of the objects of this invention to provide a safe sealing device of this character that remains safely sealed for long intervals.

.It is another object of this invention to make it possible to safeguard against escape of fluid from the housing even ii' the main seal should fail.

This result is accomplished by the provision of an intermediate low pressure chamber between the housing elements and the indicator or register which forms the load for the transmission device. When the main seal fails, this chamber is subjected to high pressure; and this pressure, in turn, is used to seal ofi the low pressure chamber from the atmosphere.

It is another object of this invention to provide a motion transmission mechanism from the interior to the exterior of s. housing device, which mechanism provides an indication in the event of a failure of the seal.

This eiect is readily secured by the aid of the pressure that exists in the intermediate chamber upon such failure. This abnormal pressure may be used to disconnect the register from the meter.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a" consideration of several embodiments of the invention. For this purpose there are shown a few forms in the drawings accompanying and forming part of the present specication. These forms will now be described in detail, illustrating the general principles of the invention; but it is to he understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a view, mainly in longitudinal section, of a transmission system incorporating the invention, some of the parts being shortened to reduce the size of the figure; and

Figs. 2 and 3 are fragmentary, enlarged sectional views of modified forms of the invention.

The transmission mechanism is shown as a metering element l. This metering element lncludes a rotary member having an output axis 2 of rotation. Since such metering elements may take any of a variety of forms, it is necessary merely to state that the metering element is cam pable of exerting a torque on a shaft 3 about the axis 2, the angular motion of the metering ele ments and of shaft 3 being proportional to the volume of the iluid passing through the meter.

The metering elements may be enclosed in a body or casing 4. The motion of the metering element is finally registered upon a register or indicator 5 external of the casing d.

The invention relates more particularly to the mechanism interposed' between the register d and the metering element i. In the present instance, a rod 6 forms one of the parts of the transmission from the metering element to the register 5. This rod may be aptly termed a nutating rod. It is arranged in such a way that its axis i describes a double cone of revolution, the apex d of the double cone fallingr on the axis 2 of the metering element i.

Accordingly, if the lower end oi the rod t is coupled to a crank 9, or the like, rotated by the metering element, the upper end of the rod can be used to impart rotation to a shaft itl. This shaft Il), in turn, as hereinafter explained, is mechanically coupled to drive the register ii.

Axial movement of shaft it may occur (as will be described hereinafter) in response to certain conditions of operation.

It is essential to provide a seal for the body around the rod 6. For this purpose, use is made of a. rubber-like diaphragm ii which may loeI made, for example, of Hycar, a well known syrithetic rubber-like material. This material is cone of revolution. serves to nex the central por@ tion ofthe diaphragm ii about a circle at the base of the sleeve. The sleeve i2 is thus angularly moved about the metering element axis 2;

In order to seal the edge of diaphragm ii against the external surface i5 of the housing il,

use is made of a reinforcing collar it disposed above the diaphragm i i. In this way, even under the extremely high pressures that may be en countered, there is no danger that the diaphragm i i will be extruded out of the casing d. and, since the sleeve i2 is directed inwardly in casing d, the high pressures therein are impressed upon the external sleeve surfaces to tighten the seal around rod d.

The collar it is shown as disposed in the bottom portion of a hollow member or housing il that forms an intermediate low pressure chamber iSl.A

This hollow member il may be provided with a shoulder i9 against which a sealing washer or gasket 2@ may be disposed. The collar it is shown as confined between the gasket d@ and the diaphragm ii. Appropriate fastening means may be utilized to hold theLhollow member il rmly upon the body d. Furthermore, the collar it may be provided with a conical central aperture 2i 'to provide a clearance for the rod d as it describes its motion..

The upper end of rod il is shown as accommodated in a slot 22 of a collar 2l attached to the lower end of shaft it. Accordingly, for each vcomplete revolution of crank t, one revolution is imparted to the shaft ill.

Shaft id is shown as extending through the upper wall of the member il. To permit ready rotation of shaft id, a ball bearing structure d is disposed in a recess in the upper wall of housing il. This structure 2d, which is a Vcombination radial and thrust bearing, has an inner race 25 through which the shaft i@ has a sliding nt. Outer race 2t is restrained against axial movement by a washer El having its inner edge extend ing inwardly over the race 25. Externally of the housing il a spur gear l@ ls keyed to the shaft ill and is normally in mesh with the spur gear 2t that drives the register Ex The hub of gear wheel 28' may rest directly upon the inner race 25; thus, l

the weight of the shalt and its associated parts can maintain the shaft i@ in the iull line position shown. j V

By means of gears 2t and 2s, the register 5 is operated'in accordance with the cyclic rnoveel ment oi rod ii.

While shaft i@ may be urged downwardly to be in operative relation with the rod t merely by its own weight, a supplemental resilient force may be used. Thus, a compression spring dit is provided. It is housed in a barrel ti fastened, as by aid of nan'ge 32, to a fiat cover plate 3s. This cover plate .extends over the gear con'iparfl ment 3i formed by walls 35 extending above housing il. The spring Bil acts upon a ball bearing structure 36 arranged around the upper end of shaft i0. The outer race ill, against which spring 30 rests, is slidable in barrel 3i. The inner race il@ is fastened to the shaft i@ and against the upper surface of the hub for wheel 28, as by n washer la and a cap screw dil. The spring 3u thus constantly exerts a pressure in an axial direction on shaft it; and, furthermore, a supplemental bearing is provided for shaft ill.

In the event the seal around rod t should fail, the intervening low pressure chamber i8. would receive the fluid under pressure from casing 4. This abnormally high pressure in chamber I8 can then act upon the collar 23 as a piston, to urge the shaft it upwardly. -At the same time'. a sealing washer 4 i, interposed between the collar 23 and the upper wall of the member I1, is placed into sealing contact with respect to the collar 23, and thus the the atmosphere. To effect a good seal, the upper surface of collar 23 carries a sharp edged ange t2 that is urged into the lower surface of washer di.

The upper position of in the dot-and-dash lines in Fig. 1. The axial movement of the shaft i@ operates to move the spur gear 28 out of mesh with spur gear 29, and register d stops because the collar 23 moves out of engagement with rod t. This disengagement' between rod 6 andthe register operating mechanism is important, since thereby the meter shaft 3 can continue to rotate without danger of breaking any of the transmission elements. Further. more, since register 5 stops, there is an indication that the diaphragm ii has failed.

The rod 5 is purposely made of such length that it is insuicient to maintain connection between cranlr t and collar il when the collar moves upwardly to the sealing position.

In Fig. 2 a slightly different form of support for the nutating rod is indicated. In this form the rod dil, corresponding to rod t in Fig. 1, is shown as having a collar dil provided with a, spherical surface. This surface is centered at point lt. This spherical surface is shown as urged against a corresponding spherical surface 45, formed in the lowe;` portion oi the reinforcing collar it disposed above diaphragm ii.

In the form illustrated in Fig. 3, the "nutating. rod il is shown as having a collar 48 similar to collar lid in Fig. 2. Rolling elements, such as ball bearing elements t9, are interposed between the collar d8 and the spherical surface 50 of the reinforcing collar 5i. A ring 52 is shown in this instance to retain the :ball bearings 49 against ,dropping out from between the collar 48 and the spherical surface bil. The aperture 53 in collar di is small enough to prevent egress of the balls d@ therethrough.

When the forms shown in Figs. 2 and 3 are used, the nutating rod is deiinitely restricted against any motion except to describe the conical paths about the apex t.

The inventors claim:

l. In a transmission mechanism: a fluid-tight housing subjected to pressure; a movable element within the housing; a load; a mechanical connection between the element and the load; means forming an intermediate low pressure chamber between the element and the load; and means on abnormal pressure in said chamber.

2. In a transmission mechanism: a fluid-tight housing; a load; means forming a low pressure chamber between the housing and the load; and

uid is kept from escaping to the shaft lu is indicated a mechanical transmission extending from inside the housing and through the chamber, including an axially movable shaft extending from the chamber and normally coupled to the load; and means responsive to the existence of abnormal pressure in the chamber for urging the shaft axially outwardly, whereby the drive to the load is interrupted.

3. In a vtransmission mechanism: a fluid-tight housing; `a load; means forming a low pressure chamber between the housing and the load; and a mechanical transmission extending from inside the housing and through the chamber, including an axially movable shaft extending from thev chamber and normally coupled to the load; a gear wheel carried by the shaft for driving the load; and means responsive to the existence of abnormal pressure in the chamber for urging the shaft axially outwardly of the chamber for moving said wheel out of driving relation to the load.

4. In a transmission mechanism: a driver; a housing therefor; a. rod connected to the driver and extending out of the housing, the axis of said rod, when driven by the driver, describing a. double cone of revolution about an apex without any angular motion about its own axis; a resilient diaphragm for sealing said housing and having an integral sleeve through which the rod passes near said apex; a load; means forming a lowpressure chamber between the load and the driver; a shaft extending into the chamber and adapted to drive the load; a collar on the shaft engaged by the outer end of the rod for rotating the shaft; and a. seal disposed'around the shaft and urged into sealing relation to the shaft upon the occurrence of abnormal pressure in the chamber.

5. In a transmission mechanism, a rod; means for driving the rod so that the axis of the rod describes a double cone of revolution; means for supporting the rod; a driving element co-operating with one end of the rod; and a driven element co-opei'ating with the other end of the rod; the coupling between the rod and the elements being disengageable by mere relative movement between the rod and the elements in a direction corresponding to the axis of the double cone; said rod being of such length that materialy relative disengaging movement between the driving `and driven elements causes one or both of said elements to become disengaged from the rod.

FRANCIS W. GUIBERT. FREDERIC B. FULLER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

